Big Bullies Hill Goblins are especially nasty and aggressive, and love nothing better then showing off and bullying smaller Goblinoids such as Kobolds and Night Goblins. To represent this, if your army includes any other types of Goblins (including Hobgoblins) then the Hill Goblins will fail their Animosity tests on a 1 or a 2 rather than just a 1 (see pages 8-9 of the Orc & Goblin army for details of Animosity). Note this rule only applies if your army does NOT include any Orc units. Even Hill Goblins know their place and will avoid getting into a brawl with an Orc!
Fear Elves Fear Elves: All Goblins dislike fighting Elves of any kind because they 'stink funny and because their haughty manner unnerves the little greenskins. A unit of Goblin troops therefore fears any unit of Elves that it does not outnumber by at least two to one. Count any Orcs. Squigs or anything else in the unit as well as the Gobbos. See pages 10-41 of the Warhammer rulebook for the rules on Unit Strength. The rules for fear an on page 81 of the Warhammer rulebook.